4,162 research outputs found
Recommended from our members
Combination antiretroviral therapy improves cognitive performance and functional connectivity in treatment-naĂŻve HIV-infected individuals.
Our study aimed to investigate the short-term effect of combination antiretroviral therapy (cART) on cognitive performance and functional and structural connectivity and their relationship to plasma levels of antiretroviral (ARV) drugs. Seventeen ARV treatment-naïve HIV-infected individuals (baseline mean CD4 cell count, 479 ± 48 cells/mm3) were age matched with 17 HIV-uninfected individuals. All subjects underwent a detailed neurocognitive and functional assessment and magnetic resonance imaging. HIV-infected subjects were scanned before starting cART and 12 weeks after initiation of treatment. Uninfected subjects were assessed once at baseline. Functional connectivity (FC) was assessed within the default mode network while structural connectivity was assessed by voxel-wise analysis using tract-based spatial statistics (TBSS) and probabilistic tractography within the DMN. Tenofovir and emtricitabine blood concentration were measured at week 12 of cART. Prior to cART, HIV-infected individuals had significantly lower cognitive performance than control subjects as measured by the total Z-score from the neuropsychological tests assessing six cognitive domains (p = 0.020). After 12 weeks of cART treatment, there remained only a weak cognitive difference between HIV-infected and HIV-uninfected subjects (p = 0.057). Mean FC was lower in HIV-infected individuals compared with those uninfected (p = 0.008), but FC differences became non-significant after treatment (p = 0.197). There were no differences in DTI metrics between HIV-infected and HIV-uninfected individuals using the TBSS approach and limited evidence of decreased structural connectivity within the DMN in HIV-infected individuals. Tenofovir and emtricitabine plasma concentrations did not correlate with either cognitive performance or imaging metrics.ConclusionsTwelve weeks of cART improves cognitive performance and functional connectivity in ARV treatment-naïve HIV-infected individuals with relatively preserved immune function. Longer periods of observation are necessary to assess whether this effect is maintained
Magnetic surface on nonmagnetic bulk of electride Hf2S
Recent experiment reported the self-passivated electride Hf2S with excellent
stability and continuous electrocatalytic ability [S. H. Kang et al., Sci. Adv.
6, eaba7416 (2020)]. Starting from its 2H-type layered structure, we have
studied the electronic, magnetic, and transport properties of the electride
Hf2S in the monolayer and multilayer forms by combining first-principles
electronic structure calculations and Kubo formula approach. Our calculations
indicate that these thin films of Hf2S electride are both dynamically and
thermodynamically stable. Astonishingly, the calculations further show that the
outmost Hf atoms and the surface electron gas of the Hf2S multilayers are spin
polarized, while the inner Hf atoms and the electron gas in the interlayer
regions remain nonmagnetic. Due to the magnetic surface, the multilayer Hf2S
exhibits many unusual transport properties such as the surface anomalous Hall
effect and the electric-field-induced layer Hall effect. Our theoretical
predictions on Hf2S call for future experimental verification.Comment: 5 pages, 5 figures, 34 reference
Poly[[hemi-ÎĽ4-oxalato-hemi-ÎĽ2-oxalato-bisÂ(ÎĽ3-pyrazine-2-carboxylÂato)erbium(III)silver(I)] monohydrate]
The asymmetric unit of the title complex, {[AgEr(C5H3N2O2)2(C2O4)]·H2O}n, contains one ErIII atom, one AgI atom, two pyrazine-2-carboxylÂate (pyc) ligands, two half oxalate ligands (each lying on an inversion center) and one uncoordinated water molÂecule. The ErIII atom is coordinated by two O atoms and two N atoms from two pyc ligands, one O atom from a third pyc ligand and four O atoms from two oxalate ligands in a distorted monocapped square-antiÂprismatic geometry. The AgI atom is coordinated by two N atoms from two pyc ligands, one O atom from a third pyc ligand and one O atom from one oxalate ligand. The crystal structure exhibits a three-dimensional heterometallic polymeric network. O—Hâ‹ŻO hydrogen bonding between the uncoordinated water molÂecule and carboxylÂate O atoms is observed
The Viscoelasticity Model of Corn Straw under the Different Moisture Contents
Viscoelastic model of corn straw, based on different moisture contents, is set up to characterise the deformation through three-point bending test. The model contains a linear elastic element, a damping element, and a nonlinear elastic element. The parameters of the model are determined according to the features of three-point bending test curve and characteristic of the model. The relationships between mechanical properties, energy absorption behavior of corn stalk, and moisture content have been, respectively, analysed. And regression analysis and curve fitting have been conducted based on various parameters and moisture contents with Matlab. These parameters provide the basis for straw crushing equipment design
Protective Effects of Squid Ink Extract Towards Hemopoietic Injuries Induced by Cyclophosphamine
To investigate the protective effects of squid ink in chemotherapy, BALB/c mice were used as animal models of injuries induced by cyclophosphamine, a well known chemotherapeutic drug. The mice were randomly divided into five groups with the same number of males and females in each group. At the end of the experiment, animals were sacrificed to investigate organ indexes and antioxidant ability of the spleen, peripheral blood profile and quantities of bone marrow nucleated cells. Results showed that the hemopoietic function of mice was injured by cyclophosphamine, as indicated by decreases of contents of erythrocytes, leukocytes, hemoglobin and bone marrow nucleated cells (P<0.01), while platelets were not affected (P>0.05), as well as modification of organ indexes (P<0.05) and spleen antioxidant ability (P<0.05 or P<0.01), whereas sepia extract markedly increased the levels of erythrocytes, leukocytes, hemoglobin and bone marrow nucleated cells (P<0.01), but not platelets (P>0.05), and reversed the effects of cyclophosphamine on organ indexes and antioxidant ability of spleen (P<0.01 or P<0.05). In addition, squid ink extract did not change marrow hemopoiesis but improved the antioxidant ability of spleen in the animals. The data suggest that squid ink extract can protect the hemopoietic system from chemotherapeutic injury and could be employed to develop cell-protective drugs for use in clinical treatment of tumours
Accelerated Nuclear Magnetic Resonance Spectroscopy with Deep Learning.
Nuclear magnetic resonance (NMR) spectroscopy serves as an indispensable tool in chemistry and biology but often suffers from long experimental time. We present a proof-of-concept of application of deep learning and neural network for high-quality, reliable, and very fast NMR spectra reconstruction from limited experimental data. We show that the neural network training can be achieved using solely synthetic NMR signal, which lifts the prohibiting demand for large volume of realistic training data usually required in the deep learning approach
- …